Strathmore: 300 Series Tracing paper. 25 lb .0016"
Mead: #54200, tracing paper. No weight listed, .0017"
Office Depot brand: item 345854. Vellum, 16 lb. 100% cotton, white translucent paper, .0025"
Staedtler: Bought at Office Depot. Vellum, 25% cotton .0027"
Mead: # 38102 Medium weight, erasable bond typing paper. .0028"
..................Buckshot